The bbc has vowed to "exercise considerable care" over bad language in a victory for the Mirror's campaign to crackdown on swearing on TV.

The corporation's governors, the BBC Trust, yesterday upheld complaints about Jonathan Ross turning the airwaves blue with his liberal use of the f-word on his chat show.

It also slammed the potty-mouthed star for his part in the Manuelgate scandal, which it called "grossly offensive". Russell Brand, 33, quit over the "prank" and two radio chiefs lost their jobs.

Bbc Trust chairman Sir Michael Lyons said: "Let me be absolutely clear. There is no place on the BBC for casual and gratuitous use of the most offensive language without clear editorial justification."

But the mistakes which led to the scandal were not isolated failings, warned the trust. It identified four programmes which included offensive material.

On Friday Night With Jonathan Ross broadcast on May 8, the chat show host made sexual remarks to Gwyneth Paltrow and asked a clearly embarrassed Michael Aspel if he'd ever "f*****" the contestants in Miss World.

Two episodes of Russell Brand's Radio 2 show were slammed over their Manuelgate content and Chris Moyles Radio 1 show was criticised for broadcasting a "suggestive" interview with Brand when as many as 300,000 kids were listening.

After the mauling by the corporation's watchdog, BBC top brass announced they would ensure editorial guidelines out next year would be stricter to stop gratuitous and unnecessary on-screen swearing.

It means Wossy, 48, due to return to the airwaves in the New Year, will be BANNED from using the f-word on his show.

A statement from the BBC said it "accepted in full" the report's findings and pledged that "management will exercise considerable care over the use of language, especially the most offensive words or phrases".

However, with the threat of a possible £250,000 fine from broadcast watchdog Ofcom hanging over the corporation, it was quick to announce that a group of execs - led by BBC creative director Alan Yentob and former BBC 2 boss Roly Keating - are already working on drawing up "appropriate boundaries of standards and taste".

Since the start of November, the Mirror has responded to disgusted readers who said swearing from stars including Jamie Oliver, Russell Brand and even squeaky-clean Ant and Dec were forcing them to switch off. ITV boss Michael Grade thrust the issue under the spotlight after admitting swearing on TV was now "unrestrained".

Since then ITV's director of programmes Peter Fincham has said "it is an area we will look at closely".

Our campaign also has the backing of the three major political parties and telly legends, including Terry Wogan.

The only mainstream terrestrial channel now not supporting our campaign is Channel 4 which has vowed to "carry on swearing".

SHOWS UNDER FIRE

1 Friday Night with Jonathan Ross, BBC1, May 2: Ross used the word "f***" in a sexual context in interviews with Michael Aspel and Gwyneth Paltrow, right. He said to Paltrow: "If you want to have sex, I'll phone my wife. If she gave me permission, I would f*** you." TRUST VERDICT: Use of the obscenity was "gratuitous and offensive" and not editorially justified.

2 The Russell Brand Show, Radio 2, October 18: Messages left on Andrew Sachs's mobile phone were broadcast, including Ross saying that Brand had "f*****" his granddaughter, Georgina Baillie. The programme was cleared for broadcast by Radio 2 controller Lesley Douglas after she was assured Sachs was happy about it. VERDICT: Grossly offensive, humiliating to Sachs and Miss Baillie. No justification for broadcast.

3 The Chris Moyles Show, Radio 1, October 21: In a live interview at 8.23am, Brand told Moyles: "I phoned up Andrew Sachs to apologise for a matter live on radio and Jonathan Ross blurted out an expletive regarding his granddaughter, who I'd, in inverted commas, recently 'met'. I met her brains out." VERDICT: Infringed the privacy of Sachs, right, and Miss Baillie.

4 The Russell Brand Show, Radio 2, October 25: Brand made a light-hearted apology to Sachs for using a swear word. He also played back a song in which he claimed to have slept with Miss Baillie. In a discussion with a guest, rapper Dizzee Rascal, there were further "intrusive and offensive" references to Brand's relationship with her. VERDICT: The "so-called apology" was unacceptable and exacerbated the situation.